Miss. Code Ann. § 31-7-421

The chief procurement officer shall establish a common date and time for the submission of best and final offers. Best and final offers shall be submitted only once; however, the chief procurement officer may make a written determination that it is in the state’s best interest to conduct additional discussions or change the state’s requirements and require another submission of best and final offers. Otherwise, no discussion of or changes in the best and final offers shall be allowed before the award. Offerers shall also be informed that if they do not submit a notice of withdrawal or another best and final offer, their immediate previous offer will be construed as their best and final offer.